H, W = map(int, input().split())
m = []
for i in range(H):
    s = list(input())
    m.append(s)

mod = 10**9+7
for i in range((H+W-1)//2):
    u, d = set(), set()
    sm = i
    for j in range(i+1):
        p, q = sm-j, j
        u.add(m[p][q])
        d.add(m[H-1-p][W-1-q])
    g = u.intersection(d)
    for j in range(i+1):
        p, q = sm-j, j
        if m[p][q] not in g:
            m[p][q] = '#'
        if m[H-1-p][W-1-q] not in g:
            m[H-1-p][W-1-q] = '#'

cnt = [[0]*W for _ in range(H)]
cnt[0][0] = 1
for i in range(H):
    for j in range(W):
        if i == j == 0:
            continue
        if m[i][j] == '#':
            break
        else:
            if i == 0 and m[i][j-1] != '#':
                cnt[i][j] += cnt[i][j-1]
            elif j == 0 and m[i-1][j] != '#':
                cnt[i][j] += cnt[i-1][j]
            else:
                if m[i-1][j] != '#':
                    cnt[i][j] += cnt[i-1][j]
                if m[i][j-1] != '#':
                    cnt[i][j] += cnt[i][j-1]
            cnt[i][j] %= mod

print(cnt[-1][-1])